Electrolyte for lithium-sulfur battery and lithium-sulfur battery comprising same

Abstract

The electrolyte solution for a lithium-sulfur battery according to the present invention exhibits excellent stability, and may improve a swelling phenomenon by suppressing gas generation during lithium-sulfur battery operation.

The invention claimed is: 
     
       1. A lithium-sulfur battery comprising:
 a positive electrode, wherein the positive electrode comprises a positive electrode active material, which comprises a sulfur series material having sulfur-sulfur bonds; 
 a negative electrode; 
 a separator, wherein the separator is interposed between the positive electrode and the negative electrode; and 
 an electrolyte solution, wherein the electrolyte solution comprises:
 a lithium salt; 
 a non-aqueous solvent; and 
 a radical adsorbent, 
 
 wherein the radical adsorbent is selected from the group consisting of: simazine, N1,N4-diphenylbenzene-1,4-diamine, and combinations thereof. 
 
     
     
       2. The lithium-sulfur battery of  claim 1 , wherein the radical adsorbent is included in 0.01% to 5% by weight based on 100% by weight of the electrolyte solution. 
     
     
       3. The lithium-sulfur battery of  claim 1 , wherein the non-aqueous solvent is one or more types selected from the group consisting of carbonate-based solvents, ester-based solvents, ether-based solvents, ketone-based solvents, alcohol-based solvents and aprotic solvents. 
     
     
       4. The lithium-sulfur battery of  claim 1 , wherein the lithium salt includes one type selected from the group consisting of LiCl, LiBr, LiI, LiClO 4 , LiBF 4 , LiB 10 Cl 10 , LiPF 6 , LiCF 3 SO 3 , LiCF 3 CO 2 , LiC 4 BO 8 , LiAsF 6 , LiSbF 6 , LiAlCl 4 , CH 3 SO 3 Li, CF 3 SO 3 Li, (CF 3 SO 2 ) 2 NLi, (C 2 F 5 SO 2 ) 2 NLi, (SO 2 F) 2 NLi, (CF 3 SO 2 ) 3 CLi, chloroborane lithium, lower aliphatic carboxylic acid lithium, lithium tetraphenylborate, lithium imide and combinations thereof. 
     
     
       5. The lithium-sulfur battery of  claim 1 , wherein the lithium salt is included in a concentration of 0.2 M to 2.0 M. 
     
     
       6. The lithium-sulfur battery of  claim 1 , further comprising an additive having N—O bonds in a molecule. 
     
     
       7. The lithium-sulfur battery of  claim 6 , wherein the additive is one or more types selected from the group consisting of lithium nitrate, potassium nitrate, cesium nitrate, barium nitrate, ammonium nitrate, lithium nitrite, potassium nitrite, cesium nitrite, ammonium nitrite, methyl nitrate, dialkyl imidazolium nitrate, guanidine nitrate, imidazolium nitrate, pyridinium nitrate, ethyl nitrite, propyl nitrite, butyl nitrite, pentyl nitrite, octyl nitrite, nitromethane, nitropropane, nitrobutane, nitrobenzene, dinitrobenzene, nitropyridine, dinitropyridine, nitrotoluene, dinitrotoluene, pyridine N-oxide, alkylpyridine N-oxide and tetramethylpiperidinyloxyl. 
     
     
       8. The lithium-sulfur battery of  claim 6 , wherein the additive is included in 0.01% to 10% by weight based on 100% by weight of the electrolyte solution. 
     
     
       9. An electrolyte solution for a lithium-sulfur battery, comprising:
 a lithium salt; 
 a non-aqueous solvent; and 
 a radical adsorbent, 
 wherein the radical adsorbent comprises an amine-based compound which is simazine, N1,N4-diphenylbenzene-1,4-diamine, or combinations thereof.